In portable electronic devices having acoustic elements (e.g., cellular phones, two-way radios, etc.), advances in piezo-electric speakers have increased the audio fidelity experienced by end users. However, piezo-electric speakers generally require large voltages (e.g., greater than 10 VRMS) to provide high fidelity audio. These high voltages present challenges in the context of portable devices, which generally use low voltage power sources to preserve battery power. Such devices have addressed this issue by employing a voltage booster, which, in turn, powers an amplifier to amplify the audio signal to power the piezo-electric speaker(s). Known audio amplifiers employ a coupling capacitor to drive a single ended load. Alternatively, the power amplifier may be provided with a regulator or a charge pump to provide a second negative voltage supply.